The present invention relates to a cartridge feeding mechanism for a gun in which the incoming cartridge is fed along the barrel axis and chambered without ramping. This is done by making the bolt "disappear" from the axis of the barrel during chambering of the cartridge.
In prior art semiautomic and automatic gun mechanisms using pushout links, such as the M60 machinegun for example, the cartridge magazine or belt feed mechanism places the cartridge as close to the bore axis as the bolt will permit. This is desirable so there is a least possible angular movement or ramping to the cartridge during chambering. However, a high percentage of gun functioning stoppages occur during chambering of the cartridge from its feed position. This is because the cartridge is difficult to control while making the transition from control by magazine or belt to control by the chamber. Aggravating this condition is the close proximity of the ejection port which provides a potential for loss of proper control by the feed mechanism during chambering.
In other prior art mechanisms, such as used in Browning and Maxim machineguns, the cartridge is extracted rearwardly from the ammunition belt and positively controlled during the chambering, extraction and ejection processes. These mechanisms provide extremely reliable feeding and chambering but they are bulky and require somewhat elaborate loading and unloading procedures which are objectionable from a training and safety viewpoint.